[TowerTalk] HF beam against the wind.

>The question of whether less stress is placed on the entire antenna
>structure [tower, beam, rotor, brake, guys etc.] by rotating the
>element ends into the prevailing wind and taking the brunt of the
>wind's force on the boom or allowing the beam to windmill and take the
>wind load broadside across all the elements... I guess can only be
>answered by the experience of the people who have tried thing both ways.
Great Falls, Montana has the highest daily average windspeed of any city
over 50,000 pop. in the lower 48 (Book of lists a few years ago). We get
frequent 60-70 mile an hour wind gusts. To clean aluminum we just put it
out in the wind and let it get sandblasted (as suggested by KE7X in
relatively calm Bozeman, 200 miles to the south). Everybody around here
(all 5 or 6 of us) lets their booms take the wind.
Another reason to do this was shown to me 2 days ago. We had a nice little
breeze blowing out of the NW. I walked outside and happened to look up at
the 205 at 83 feet. The elements were resonating in the wind like I had
never seen before. I mean they were whipping up and down like fishing rods
at a fly fishing tournament! I immediately turned the elements away from
the wind and this potentially destructive motion ceased. It's these
low/medium speed "resonating" breezes that cause those element ends to
shake loose of your antennae. A case for rivets, I suppose.
73, Matt--K7BG
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